p-values and Confidence Intervals
ST551 Lecture 9

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p-values

p-values

A p-value associated with a hypothesis test of some null hypothesis \(H_0\) vs. some alternative \(H_A\) is the probability, under the null hypothesis, of observing a result at least as extreme as the statistic you observed.

We estimate that the mean time OSU freshman (Fall 2017) spent preparing for class was 25.7 hours per week.

With 95% confidence, the mean time OSU freshman spend preparing for class is between 24.72 and 26.68 hours per week.

use p-value rounded to 2 significant figures if > 0.001

Your turn:

A random sample of \(n = 25\) Corvallis residents had an average IQ score of 104. Assume a population variance of \(\sigma^2 = 225\). What’s the mean IQ for Corvallis residents? Is it plausible the mean for Corvallis residents is greater than 100?